Motorola roundie

[timmy]

Originally Posted by Yamamaya42

https://hackaday.com/2018/01/18/know...ideo-waveform/



It's exactly what happened with with my CTC-16XL, I had color with direct input video, but not from tuner, a messed up IF WILL BLOCK color, cause the timings getting to the color circuit will be distorted, in my case, the 4.5 mhz trap was WAY out of tune, blocking all color, leaving a perfect BW screen, the IF on mine is still not fully right, but works well enough.

But yes, a borked IF can distort the colorburst signal timing, leaving just a BW screen, this can be tested by once again removing the 3rd If, and putting in direct video at test point B , as you have done in the past, if you see no color, then it's the color circuits, if you do, then is a problem before the color circuits.

The 41.25 trap was the big problem I had originally and never had to mess with the IF in the first place so I can try to tweak the trap and see.